Cold foil on pressure-sensitive labels works as a system, not as a single material choice. The face material, the cold-transfer adhesive, the foil, the curing equipment and any overprint or finishing all have to suit each other on the converter's own press. This guide is for label converters planning that selection and preparing a trial. CFS supplies cold transfer foil rolls; adhesive, UV curing, anilox rolls and printing equipment come from your other suppliers, and CFS does not sell finished labels.
What makes up a cold-foil label construction?
A cold-foil label is built in layers: the label face material, a printed adhesive image, the transferred foil, and often process-color overprint, varnish or lamination. Each layer can be supplied by a different company, which is why compatibility is something to confirm and record rather than assume.
In a typical UV flexo process, adhesive is printed in the foil image, the foil comes into contact with it, the adhesive is cured as the materials' suppliers specify, and the carrier film is peeled away. KURZ's flexo cold-transfer FAQ describes this sequence and notes that all components, from the adhesive to the substrate to the transfer product, should be ideally matched. Actual equipment layouts differ between presses, so treat any description as a general outline and follow the documents for your own materials and equipment.
How is cold-foil adhesive different from label adhesive?
They are different materials with different jobs. The pressure-sensitive adhesive on the back of a label sticks the finished label to its container. The cold-transfer adhesive is printed on the front in the foil image and is what the foil bonds to during transfer. Selecting one does not select the other, and a data sheet for one cannot be used to judge the other.
For adhesive and cure questions, see the UV cold foil adhesive selection guide, which covers what to ask adhesive and equipment suppliers.
How do foil, adhesive and equipment need to match?
Foil, adhesive and curing equipment are normally confirmed together. Foil suppliers publish grades for particular applications, and substrate suitability is typically confirmed by the customer: API Foilmakers' TA-Plus page, for example, says suitability of the substrate for cold transfer should be confirmed by the customer. That statement is about one supplier's grade and not a general rule, but it shows why a trial on your own materials matters.
Practical consequences for a converter:
- Ask the adhesive supplier which foil and face-material combinations the adhesive is documented for.
- Ask the equipment supplier how curing should be arranged at the adhesive station for your press.
- Record the adhesive, foil and curing arrangement used in every trial so a result can be traced.
Which face materials raise which questions?
This table is a qualitative planning aid. It does not rate materials as good or bad, and it gives no smoothness, gloss or coat-weight values.
| Label face material or surface | Variables to confirm with suppliers | What to observe in the trial | Further reading |
|---|---|---|---|
| Papier revêtu | Coating type and supplier, printed surface, adhesive grade | Foil coverage, edge definition and appearance of solids and fine detail | Flexo cold foil materials |
| Uncoated or textured paper | Surface texture and absorbency, any primer or underprint, adhesive grade | Whether the surface changes foil appearance, coverage in solids and fine detail | Cold foil sur papier non couché |
| White film such as BOPP | Film brand and grade, topcoat, surface treatment record, adhesive grade | Coverage, edges and the result after the checks agreed with the buyer | Cold foil sur étiquettes BOPP |
| Clear film | Viewing direction, layer order, white backing, adhesive clarity | Appearance through the film as well as on the printed side | Cold foil for transparent labels |
How should fine detail and solid coverage be judged together?
A construction that gives clean fine lines may not give an even solid, and the reverse. Include both in the trial artwork, along with the smallest detail the design needs, and examine them on the same sample. Record the adhesive application, such as the plate and anilox used, so that a change can be compared like for like. For how to record anilox variables without relying on a universal recipe, see the guide de sélection anilox.
What happens at overprint and finishing?
Process color, white, varnish and lamination all go on top of or around the foil, and each can change appearance or adhesion. Do not assume an ink series or finish is compatible with a given foil because it is compatible with another. Keep staged samples after transfer, after overprint and after finishing so any problem can be traced to the step where it first appears. The CMJN sur guide de foil à froid explains how to plan overprint and where to check compatibility.
Cold transfer does not use a heated stamping die, but that does not mean it uses no pressure, no plate or that no equipment generates heat. Check the actual operation on your press.
What does a trial roll need to record?
A trial is only useful later if the conditions are written down. At a minimum, record:
- Face material brand, grade and printed surface.
- Adhesive supplier and grade.
- Foil grade and lot.
- Plate and anilox specification and the measured condition of the anilox.
- Curing equipment and arrangement.
- Running speed, tension and pressure settings.
- Overprint, varnish or lamination used.
- What you observed, with photographs, and who approved or rejected the sample.
Le liste de contrôle de configuration de presse et le defect diagnosis guide can help organize a trial and an investigation.
What is the next step for roll selection?
Choose the finish and viewing direction first, then confirm grade, adhesive and equipment as a system. The flexo cold foil materials page summarizes the questions to settle before you ask for a trial roll. If you are ready to plan one, send your face material, adhesive and press details to CFS and we will reply about foil supply; terms and availability are confirmed with you.
Questions fréquentes questions
Does CFS supply adhesive or printing equipment? +
No. CFS supplies cold transfer foil rolls. Adhesive, UV curing, anilox rolls and printing equipment come from other suppliers, and CFS does not sell finished labels.
Can I use label adhesive as cold-transfer adhesive? +
No. They are different materials. The pressure-sensitive adhesive on the back of a label bonds the finished label to its container; cold-transfer adhesive is printed on the front and receives the foil.
Does cold foil have to be fully cured before the foil contacts it? +
This depends on the adhesive, foil and equipment. Do not assume one sequence applies everywhere. Follow the adhesive and equipment suppliers' documentation for your press and confirm the result in a trial.
Which face materials are approved for CFS foil? +
CFS does not publish a universal approved list. Suitability is confirmed project by project with your actual face material, adhesive and press.